In the field of fitness and indoor training, as well as postural training and remedial gymnastics, the use of the so-called fitness balls or stability balls is well known to perform physical exercises to train the dorsal, lumbar and abdominal muscles while being in constant unstable balance. These exercise devices are usually comprised of a ball that is made of an artificial and partially elastic material, for instance PVC, and maintains its shape through pressurized air at a given pressure.
A fitness ball is generally used as a support for a body portion of a user executing given gymnastic exercises and is designed to be deformed, in use, under the weight of this user so as to give a substantially unstable support. In this regard it should be noted that the lack of a stable support while executing gymnastic exercises forces the user's body to continuously attempt to find a balance position in a substantially dynamic manner by making small muscle movements to balance the local deformations of the fitness ball following even small movements of the user's arms. In this way, the execution of the traditional gymnastic exercises resting on a fitness ball allows to train a greater number of muscles and specifically allows to continuously involve the muscles that are generally less involved in executing these traditional exercises. The prolonged use of a fitness ball allows therefore to tone up the muscles that are generally not stressed while executing the traditional gymnastic exercises, such as press-up, pull-up, etcetera, and using isotonic gymnastic machines like chest press or leg extension, that are designed to separately train specific muscle regions.
For the reasons described above, the fitness balls are generally used to train the dorsal and lumbar muscles and to perform postural exercises for maintaining the backbone in a correct position. To this end, the use of fitness balls and stability balls as sitting members is well known also in environments not destined for training or remedial gymnastics, such as at home or office. For instance, the use of fitness balls as seats in an office is well known when the job requires to sit for the most part of the day, for instance in the case of people using a personal computer. In these cases, the use of a fitness ball may help in maintaining a correct posture of the backbone and allows to train the muscles without interfering with or interrupting the job at the workplace.
However, the use of the current fitness balls as sitting members has many drawbacks; therefore they have not yet spread at home or office. Firstly, the artificial material of the outer shell of the fitness ball tends to be polarised very easily, for instance through friction with the user's clothes or with a carpet, and therefore to capture and holds dust and dirt through electrostatic attraction. Furthermore, this material is not breathable and causes significant perspiration of the body portion resting on it for a prolonged time, for instance for entire work shifts. Lastly, it is not possible to avoid that, following a movement made by the user for his/her home or office activity, the lower portion of the fitness ball slides or rolls with respect to the floor, thus making the user fall with possible risk of injury.
In view of the above description the problem of having available a fitness ball or a stability ball that can be used for prolonged time as a sitting member is currently unsolved, and represents an interesting challenge for the applicant, aiming at producing an exercise device that can be deformed and used in absolute safety at home or office as sitting member, at least partially unstable.
In particular, it would be advisable to have available an exercise device that, in addition to present the consistency of, and to be deformed like, a common fitness ball, also presents characteristics of being anti-static, breathable in the contact areas with the user's body, and slip-resistant in the contact areas with the floor or other support surface.
In fact, an exercise device with these features would allow overcoming the drawbacks of the prior art and defining a new standard both in the field of exercise devices and in the field of sitting members usable at home and/or office.